Submarines

Posted byRandall 664 Comments on Submarines

I’m going through a rough period right now. There’s an illness in my family and I’m having a hard time focusing on anything but worrying and trying to take care of health stuff. Everyone is going to be okay, but it’s going to be a difficult four or five months, and I really appreciate your patience and understanding. I’m going to keep putting up comics, but I don’t how much else I’ll be able to work on.

To anyone I’ve been corresponding with, I’m sorry that I may be even more tardy than usual. While davean (the xkcd sysadmin/business manager) monitors the press@xkcd.com address, I know he only forwards to me a fraction of the huge flood of mail that goes there. If you’re trying to reach me personally about something, you can write to me directly at xkcd@xkcd.com, but I’m afraid I won’t able to reply to most of it right now.

I know there haven’t been any posts here in a while. Since most of my projects are on hold right now, I thought I’d share some pictures from one that’s almost done: an underwater ROV. Exploring lakes and oceans has always fascinated me, and while I’ve spent a lot of time snorkeling and free diving, in the end I’m more interested in sending robots than going myself.

I tried to build a couple of ROVs in high school out of scavenged R/C cars and spare parts, but none of them ever worked very well. Last summer, I got interested again and picked up an Inventivity ROV-in-a-Box:

Inventivity ROVIAB

It’s a very basic kit designed to use off-the-shelf parts as much as possible, to encourage people to play with the design or expand on it. I’ve gotten a lot of help and some cool ideas from the company founder, Dr. Karen Suhm, who coaches robotics teams in ROV-building competitions and generally knows everything about ROVs. The kit comes with a good set of underwater motors and a sensitive camera, and this summer I started modifying it to use an Arduino and joystick control, running the whole thing over Cat-5 cable (which significantly lightened the tether). This will also let me add other equipment, like a still camera, depth gauge, compass, and sonar.

It’s very close to being finished—I just have a couple wires to reroute and a leak to seal—but for now, here are some pictures from construction and testing:

Hello.

I made a coupler so the tether could be detached, and added a chamber to hold the Arduino, Ethernet shield, and motor control board. A Python script on the surface translates joystick values into motor speeds, and the Arduino has some code to listen to commands via the Ethernet and control the motors using three TLE-5206 H-bridges. The 5206s offer more protection than some other H-bridges—I initially used some smaller chips, and managed to blow out a couple. (Thank you to mpanetta of #sparkfun for hooking me up with the 5206s.)

A note to anyone who wants to build something like this: the Arduino isn’t actually capable of processing video, so you’ll need to either put an Ethernet camera and hub on the rover, or—if your camera isn’t digital—do what I did and divert two of the Cat-5’s twisted pairs to carry RCA video, running the Ethernet solely on the other half.

This canoe (and everything else in the shot) travels through time.

My friend Mike loaned his canoe for depth testing in Walden Pond, which is (according to data from the 1940s) the deepest lake in Massachusetts

It's about 90 feet down from here.

At the bottom of Walden, there are close to three extra atmospheres of pressure.

In this shot, read left to right.

The zip ties double as binary depth markers. This one is 14 meters.

Shlooooop.

This is the vacuum pump for sealing up wires passing into the sub (it’s sitting atop a draft of the online communities map). If you open up the exterior/water side of a cable and submerse it in a pool of marine epoxy, then apply suction to the dry interior of the sub, it sucks the epoxy through the cable, plugging it up completely. You can also use it to suck all the air out of a wine bottle with random objects inside. It’s fun to see how different materials react to a near-vacuum—particularly if you’ve just drunk a bottle of wine. I didn’t get much more done that day.

Lastly, here’s a clip of the bottom of Walden Pond, about 80 feet below the surface.  This was an unpowered pressure test—the sub was just dangling on a rope—so it’s not very exciting, but it was the only test where I could record the video feed:

The Walden lakebed is pretty dead—the material you’re seeing is flakes of debris stirred up by the sub. In other lakes, we’ve found cooler stuff.  In Seymour Pond on Cape Cod, we had huge catfish fish swim up to the camera and look at it, and we explored a sunken fishing boat on the bottom of Sheep Pond.  I’ve also learned that deck chairs apparently fall off docks all the time—the lakebed 20 feet below the dock on one lake was absolutely littered with them.  When I get a chance to send it to some more interesting places, I’ll be sure to share footage.

P.S. A belated thank-you to the NYC Makerbotters; after I posted comic #743, they fabricated and mailed to me an actual tiny open-source violin.

664 replies on “Submarines”

  1. Good luck with your family! I’ve been there (am being there) and done (doing) that. You have my very great sympathy. Draw only when you want to, and take care of yourself as well as your family.

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  4. Focus on your family’s health. Don’t worry about us, we’ll be fine.

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  5. Sorry to hear, wishing you guys the best. I love your work, and I have it hanging in my cubicle and also one signed by you in my house. You brighten up my life. I hope your life gets brighter soon.

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  6. I empathize. My grandfather actually is going through a rough time right now. He has stage four kidney cancer, and they recently discovered a malevolent tumor in his spine. Is having surgery today to get a metal plate put in because they removed it yesterday. After that and before living at ICU for like a month, I understand what’s going on.

    Focus on your family and be with them. It’s a tough time, but try to make the best of what is going on. I know we did, though all the tears and fears.

    On another note, go robots! You’ve really given hope to us geeky 13 year olds that besides that, are shunned because we’re girls!

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  7. I dont really read the blag or check out the forums so this is the first time I hear of the illness you are dealing with in your family. I just want to say I wish you all the best and of course a very speedy recovery.

    Captcha: national Hisionce

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  10. I am very sorry to hear about the illness and wish your family the best of luck.

    On another note, related to the ROV underwater camera: You should check out Lake Winnipesaukee in Central New Hampshire. It is a massive glacial lake (deepest point is over 200 feet deep) and there are many many many well documented sunken things (everything from railroad cars, to steamboats, to speed boats). Most of the documented objects (from what I recall at least) are in less than 100 feet of water. If interested I would be happy to get you more info / maps etc.

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  12. Wow sorry to hear about the health issues. Hope everything gets better soon. Keep on drawing!

    Oh, and the homemade sub looks totally awesome. Seriously.

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  13. So sorry to hear. My thoughts go out to you. We love your wit and humor. Your comic is a regular for my boyfriend and I. Wishing you much peace and healing from two web nerds ^_^

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  14. Sorry to hear this… Atheists don’t pray, but I’ll definitely be wishing you guys best luck, and if there’s anything you might need, there’s the whole of your audience here for you 🙂

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  15. Randall, dunno if you remember me(had your lovely support on our little hack)- hope everything will be fine and all my best wishes 🙂

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  16. This too shall pass.
    Your audience will wait for you. We’ll look at past cartoons if you miss a MWF.
    There is nothing like xkcd. You are uniquely clever.

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  20. Support and good thoughts, Randall.

    If I could, I’d write you a distracting game. It’d be like Where in the World is Carmen Sandiego, except you’re following a trail of maimed bodies looking for Summer Glau to warn her about raptors. When you catch up to her you win, which unlocks a video of Summer Glau kicking raptors’ asses.

    But I was a social science major, so I’m not cool like that. (I’m cool in other ways.)

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  21. Just a small note from one of the many thousands of people who enjoy your cartoons on a regular basis, without knowing you personally. Sorry to read about your family troubles; I hope everything works out for you very soon, and will be sending good thoughts your way that it does. (((((((xkcd)))))))

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  23. I’d keep you on my Google Reader even if you only posted one comic a year. Take care of you and yours first, we’re happy with what you give when you can.

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  25. Very sorry to read about that… I hope your family can get trough this and everything works out for you.

    Be sure we will be praying/wishing you the best/expressing our support/doing whatever could be useful.

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  28. Sorry for you having tough time, Randall. I don’t know whether that is your case, but some people find quite a lot of support in music. Here’s a song that helps me, “skoro budet solnechno” (“soon there will be sunlight”) by Alexander Vasil’yev: http://cs4833.vkontakte.ru/u12619064/audio/36846234fbd3.mp3
    It is in Russian, so I don’t know if it is inspiring in the language one doesn’t know. And I don’t have enough time to make a worthy translation at the moment, so please write if you need one, I’ll come up with something. Even without the words the flute is quite nice, so I hope it’ll cheer you up a little.

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  29. Thank you for all the awesomeness that you bring into the world through this site. Creating an be a refuge in rough times and I know you’ll make it through.

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  32. Sorry to hear about your family illness, and I really hope your family member comes out of it OK and soon! In the mean time, it sounds like you’re making your family your priority, and that’s the right choice. We’ll still be here when you get back, and I’ll be catching up on the Blag until you get back.

    Best wishes and happy thoughts.

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  33. I’m sorry to hear about your family. I hope and pray for the best for you and your family.

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  35. I am sorry to hear about your family illness, I hope and pray for the best for you and your family.

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  36. Wow this looks like a great project. Looks great to check out shipwrecks and the like. Get well soon, the earth’s rotation might slow down by 50 mph if this continues (waiting for the next comic) hehe

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  37. The nice thing about the internet, is connecting out to a whole world , discovering many people who actually care because in sharing humor you also made our life better

    as such yes I can give A Taoist blessing, which is simply “embrace heart” and while in words that may not seem much, it is meant deeply as you have made me laugh so many times

    most sincerely and stand strong in your life

    if you ever need some encouragement or alternative ways at looking at things i am happy to assist (even if it means facing a pack of hungry Velociraptors, philosophy of nothingness confuses even these beasts it turns out)

    sincerely and among hundreds and thousands of those of us who care 🙂

    casey

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  38. sorry to hear. . . it should be interesting to see what random archival drawings you have for us! btw i am a physics teacher & have several of your comics hanging in my room, and have been attending a conference for science teachers the last couple days (CAST 2010) & i’ve seen several xkcd shirt wearers in the crowd 😀

    hope all goes well with the family; your comics always get me out of any shitty mood, and hopefully you’ve got something out there that will do the same for you during these times

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  39. My prayers are with you and your family Mr. Randall :3 Don’t worry about us, we’ll still be here.

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  41. XKCD has always brough so much happiness and joy (and many inside jokes) to my life and to the lives of my friends–we love you, and hope you will find that all the joy you’ve given away so freely comes back to you now. ❤

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  42. Nothing to add here except to say I’m sorry for what’s going on right now, and you & your family are in my heathen Unitarian thoughts & prayers. I figure 1 commenter = 10 lurkers, so here’s another 10 people wishing you the best.

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  43. I hope things get well soon. You are a hero and a source of inspiration for so many of us. We believe in you; don’t let this time of darkness defeat you!

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  44. Wishing and hoping for the best for you and yours. It’s hardest of all to watch one’s loved one going through so much. (I was the very ill loved one in my family last year, in the hospital for weeks, barely hanging on. I still say it was harder on them.) Gradually, we all healed. May you get to have that outcome too.

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  46. The best to you and your family, and don’t worry about the comic. I’ve intentionally not read all of the older comics, so the random button will keep all of us happy!

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  47. Best wishes for a good conclusion on you family’s difficulties. I and many friends love to catch the comic every time it updates (it’s a piece of shared culture, thanks!), but family is much more important.

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  48. Hope everything turns out ok. Don’t feel pressed by publishing something, we will wait.

    Good luck there

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  49. Pingback: links for 2010-11-12 « Donghai Ma

  50. Sad to hear about the family troubles. I went through some stuff at the end of this summer, webcomics help a bit. If you don’t mind medical references a bit you might want to check out bscomics.com

    P.S. take a break if you need one and make sure you eat/sleep enough.

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